Heretofore, in the manufacture of can bodies, processing devices which perform predetermined processing such as heating and a pinhole inspection have been used.
Such a processing device generally includes a main turret having bottom suction means and a can body holding pocket. The bottom suction means receives a can body via the can body holding pocket, and thereby holds the can body so that the bottom of the can body is centered, and the conveyed can body is then subjected to predetermined processing.
The following devices have heretofore been used as the processing devices of the above type.
A container processing device according to a first typical example is a device which provides a heat treatment to a can body, and this device is described with reference to the drawing.
FIG. 5 is a schematic diagram of essential parts for illustrating the container processing device according to the first typical example, wherein (a) shows a front view, and (b) shows a C-C sectional view.
As shown in FIG. 5, a heating device 101 includes a main turret 102 provided with a plurality of bottom suction means 21 and can body holding pockets 122, and high-frequency induction heating means 103 which provides a heat treatment to a can body 10 that is conveyed while being sucked by the bottom suction means 21.
The can body 10 having its surface coated with a coating film such as a polyester film or an organic coating film is then embossed by the heat treatment without any detachment, blanching, and cracking of an embossed design during the embossing for forming depressions and/or projections.
In this heating device 101, the can body holding pockets 122 which are fixed to the main turret 102 and which rotate together with the main turret 102 center the can body 10 received from a container supply turret 5, and the bottom suction means 21 suck the centered can body 10.
The main turret 102 then conveys the can body 10 which is rotating on its axis by the bottom suction means 21 along the high-frequency induction heating means 103, and the high-frequency induction heating means 103 heat the substantially entire side surface of the can body 10.
The heated can body 10 which has stopped rotating on its axis is then conveyed, and passed to a container conveying turret 6.
The can body 10 which has been heated in this manner is then supplied to an embossing process (not shown) for embossing to form depressions and/or projections in the can body 10.
A container processing device according to a second typical example is a device which inspects a can body for a pinhole by applying light to the can body. This device is described with reference to the drawing.
FIG. 6 is a schematic diagram of essential parts for illustrating the container processing device according to the second typical example, wherein (a) shows a front view, and (b) shows a D-D sectional view.
As shown in FIG. 6, a pinhole inspection device 101a includes a main turret 102a provided with a plurality of bottom suction means 21a and can body holding pockets 122a, and illumination means 3a, 131a, and 132a for providing pinhole inspection processing to a can body 10 that is conveyed while being sucked by bottom suction means 21a. 
Although not shown, a sealed ring plate and a camera obscura according to Patent Literature 2 described later are used in the pinhole inspection processing.
In this pinhole inspection device 101a, the can body holding pockets 122a provided in the main turret 102a center the can body 10 received from a container supply turret 5, and the bottom suction means 21a suck the centered can body 10.
The main turret 102a then conveys the can body 10 which is pressed on an opening receiver of a slide ring plate 123 by the bottom suction means 21a, and a pinhole inspection is conducted while the light is being applied to the can body 10 by the illumination means 3a, 131a, and 132a from the outside of the can body 10.
The inspected can body 10 is then conveyed so that the can body 10 has retreated from the opening receiver, and the can body 10 is passed to a container conveying turret 6.
In connection with the container processing devices described above, Patent Literature 1 discloses a technique associated with a can barrel processing method to emboss a can body having its surface coated with a coating film such as a polyester film or an organic coating film. According to this can barrel processing method, an embossing device includes a heating unit and an embossing unit. The heating unit has a pocket (can body holding pocket), a high-frequency induction heating coil device, and a chuck. A can body supply unit (container supply turret) is provided on the upstream side, and a can body passing unit is provided on the downstream side.
Patent Literature 2 also discloses a technique for a can body pinhole inspection device. This inspection device includes a turret having a slide ring plate in which a through-hole is formed, a sealed ring plate having a hole which is in communication with the through-hole, a light irradiator which irradiates the entire barrel of a can body, and a camera obscura having a photodetector therein.